Exploring subtalar joint axis alignment in pathological feet of children with cerebral palsy using weight bearing CT

Erik A. Meilak; Wouter Schallig; Andrew Roberts; Marjolein M. van der Krogt; Melinda M. E. H. Witbreuk; Mario Maas; Luca Modenese; Annemieke I. Buizer; Ruud H. H. Wellenberg; Caroline Stewart

doi:10.1016/j.jbiomech.2026.113352

Exploring subtalar joint axis alignment in pathological feet of children with cerebral palsy using weight bearing CT

Erik A. Meilak
, Wouter Schallig
, Andrew Roberts
, Marjolein M. van der Krogt^*
, Melinda M. E. H. Witbreuk
, Mario Maas
, Luca Modenese
, Annemieke I. Buizer
, Ruud H. H. Wellenberg
, Caroline Stewart

^*Corresponding author for this work

Keele University
Vrije Universiteit Amsterdam
Amsterdam UMC
Erasmus University Rotterdam
ORLAU RJAH Orthopaedic Hospital
University of Amsterdam
University of New South Wales
University of Amsterdam
School of Medicine
Amsterdam UMC Location Vrije Universiteit Amsterdam
The Netherlands
Department of Radiology and Nuclear Medicine
Erasmus MC University Medical Center Rotterdam
Amsterdam UMC location University of Amsterdam
University of New South Wales (UNSW Sydney)
Emma Children's Hospital

Research output: Contribution to journal › Article › Academic › peer-review

7 Downloads (Pure)

Abstract

The subtalar joint (STJ) is essential for proper foot functioning and fundamental to the biomechanics of this joint is its axis orientation. It is currently unknown how this orientation is altered in cerebral palsy (CP) across the range of foot deformities including varus, planovalgus and midfoot break (MFB). The aim of this study was to quantify STJ axis orientations in children with CP and typically developing (TD) children. In this multicentre study, weight-bearing CT (WBCT) data of participants (21 CP and 9 TD) were collected and foot bone surfaces were segmented. STJ axes were derived from the talar surfaces using shape fitting techniques. STJ axis medial deviation and inclination angles were measured with respect to two anterior/posterior axes, one derived from the tibia and the second from the foot. Significant differences were identified between groups in both medial deviation and inclination angles. Planovalgus feet without MFB exhibited greater medial deviation (26.2±3.2°) and lower inclination angles (18.2 ± 7.3°) than TD feet (medial deviation: 19.4±3.6° and inclination: 25.7 ± 3.8°). Children with MFB had even greater medial deviations (37.7 ± 7.2°) and lower inclinations (-1.7 ± 10.8°) with the mean STJ axis orientation switching to pointing towards the ground. Varus feet had the greatest STJ axis inclination (32.3 ± 7.7°) and the widest range of medial deviations (0.8 ± 21.5°). This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future. This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future.

Original language	English
Article number	113352
Pages (from-to)	113352
Journal	Journal of biomechanics
Volume	204
DOIs	https://doi.org/10.1016/j.jbiomech.2026.113352
Publication status	Published - 1 Jul 2026

Keywords

Humans
Cerebral Palsy/diagnostic imaging
Subtalar Joint/diagnostic imaging
Female
Weight-Bearing
Male
Child
Tomography, X-Ray Computed
Biomechanical Phenomena
Adolescent

Access to Document

10.1016/j.jbiomech.2026.113352

Exploring-subtalar-joint-axis-alignment-in-pathological-feet-of-children-with-cerebral-palsy-using-weight-bearing-ct.pdfFinal published version, 2.69 MBLicence: CC BY

Cite this

Meilak, E. A., Schallig, W., Roberts, A., van der Krogt, M. M., Witbreuk, M. M. E. H., Maas, M., Modenese, L., Buizer, A. I., Wellenberg, R. H. H., & Stewart, C. (2026). Exploring subtalar joint axis alignment in pathological feet of children with cerebral palsy using weight bearing CT. Journal of biomechanics, 204, 113352. Article 113352. https://doi.org/10.1016/j.jbiomech.2026.113352

@article{3d67ee3d9412418381919ee36db3c2b8,

title = "Exploring subtalar joint axis alignment in pathological feet of children with cerebral palsy using weight bearing CT",

abstract = "The subtalar joint (STJ) is essential for proper foot functioning and fundamental to the biomechanics of this joint is its axis orientation. It is currently unknown how this orientation is altered in cerebral palsy (CP) across the range of foot deformities including varus, planovalgus and midfoot break (MFB). The aim of this study was to quantify STJ axis orientations in children with CP and typically developing (TD) children. In this multicentre study, weight-bearing CT (WBCT) data of participants (21 CP and 9 TD) were collected and foot bone surfaces were segmented. STJ axes were derived from the talar surfaces using shape fitting techniques. STJ axis medial deviation and inclination angles were measured with respect to two anterior/posterior axes, one derived from the tibia and the second from the foot. Significant differences were identified between groups in both medial deviation and inclination angles. Planovalgus feet without MFB exhibited greater medial deviation (26.2±3.2°) and lower inclination angles (18.2 ± 7.3°) than TD feet (medial deviation: 19.4±3.6° and inclination: 25.7 ± 3.8°). Children with MFB had even greater medial deviations (37.7 ± 7.2°) and lower inclinations (-1.7 ± 10.8°) with the mean STJ axis orientation switching to pointing towards the ground. Varus feet had the greatest STJ axis inclination (32.3 ± 7.7°) and the widest range of medial deviations (0.8 ± 21.5°). This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future. This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future.",

keywords = "Humans, Cerebral Palsy/diagnostic imaging, Subtalar Joint/diagnostic imaging, Female, Weight-Bearing, Male, Child, Tomography, X-Ray Computed, Biomechanical Phenomena, Adolescent",

author = "Meilak, \{Erik A.\} and Wouter Schallig and Andrew Roberts and \{van der Krogt\}, \{Marjolein M.\} and Witbreuk, \{Melinda M. E. H.\} and Mario Maas and Luca Modenese and Buizer, \{Annemieke I.\} and Wellenberg, \{Ruud H. H.\} and Caroline Stewart",

note = "Publisher Copyright: {\textcopyright} 2026 The Authors",

year = "2026",

month = jul,

day = "1",

doi = "10.1016/j.jbiomech.2026.113352",

language = "English",

volume = "204",

pages = "113352",

journal = "Journal of biomechanics",

issn = "0021-9290",

publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Exploring subtalar joint axis alignment in pathological feet of children with cerebral palsy using weight bearing CT

AU - Meilak, Erik A.

AU - Schallig, Wouter

AU - Roberts, Andrew

AU - van der Krogt, Marjolein M.

AU - Witbreuk, Melinda M. E. H.

AU - Maas, Mario

AU - Modenese, Luca

AU - Buizer, Annemieke I.

AU - Wellenberg, Ruud H. H.

AU - Stewart, Caroline

PY - 2026/7/1

Y1 - 2026/7/1

N2 - The subtalar joint (STJ) is essential for proper foot functioning and fundamental to the biomechanics of this joint is its axis orientation. It is currently unknown how this orientation is altered in cerebral palsy (CP) across the range of foot deformities including varus, planovalgus and midfoot break (MFB). The aim of this study was to quantify STJ axis orientations in children with CP and typically developing (TD) children. In this multicentre study, weight-bearing CT (WBCT) data of participants (21 CP and 9 TD) were collected and foot bone surfaces were segmented. STJ axes were derived from the talar surfaces using shape fitting techniques. STJ axis medial deviation and inclination angles were measured with respect to two anterior/posterior axes, one derived from the tibia and the second from the foot. Significant differences were identified between groups in both medial deviation and inclination angles. Planovalgus feet without MFB exhibited greater medial deviation (26.2±3.2°) and lower inclination angles (18.2 ± 7.3°) than TD feet (medial deviation: 19.4±3.6° and inclination: 25.7 ± 3.8°). Children with MFB had even greater medial deviations (37.7 ± 7.2°) and lower inclinations (-1.7 ± 10.8°) with the mean STJ axis orientation switching to pointing towards the ground. Varus feet had the greatest STJ axis inclination (32.3 ± 7.7°) and the widest range of medial deviations (0.8 ± 21.5°). This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future. This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future.

AB - The subtalar joint (STJ) is essential for proper foot functioning and fundamental to the biomechanics of this joint is its axis orientation. It is currently unknown how this orientation is altered in cerebral palsy (CP) across the range of foot deformities including varus, planovalgus and midfoot break (MFB). The aim of this study was to quantify STJ axis orientations in children with CP and typically developing (TD) children. In this multicentre study, weight-bearing CT (WBCT) data of participants (21 CP and 9 TD) were collected and foot bone surfaces were segmented. STJ axes were derived from the talar surfaces using shape fitting techniques. STJ axis medial deviation and inclination angles were measured with respect to two anterior/posterior axes, one derived from the tibia and the second from the foot. Significant differences were identified between groups in both medial deviation and inclination angles. Planovalgus feet without MFB exhibited greater medial deviation (26.2±3.2°) and lower inclination angles (18.2 ± 7.3°) than TD feet (medial deviation: 19.4±3.6° and inclination: 25.7 ± 3.8°). Children with MFB had even greater medial deviations (37.7 ± 7.2°) and lower inclinations (-1.7 ± 10.8°) with the mean STJ axis orientation switching to pointing towards the ground. Varus feet had the greatest STJ axis inclination (32.3 ± 7.7°) and the widest range of medial deviations (0.8 ± 21.5°). This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future. This study presents STJ axis alignment in CP for the first time. The use of WBCT imaging has identified changes in alignment of key foot bones, with potential for more detailed biomechanical analysis (e.g. muscle moment arms) and individualised management in the future.

KW - Humans

KW - Cerebral Palsy/diagnostic imaging

KW - Subtalar Joint/diagnostic imaging

KW - Female

KW - Weight-Bearing

KW - Male

KW - Child

KW - Tomography, X-Ray Computed

KW - Biomechanical Phenomena

KW - Adolescent

UR - https://www.scopus.com/pages/publications/105040215246

U2 - 10.1016/j.jbiomech.2026.113352

DO - 10.1016/j.jbiomech.2026.113352

M3 - Article

C2 - 42217261

SN - 0021-9290

VL - 204

SP - 113352

JO - Journal of biomechanics

JF - Journal of biomechanics

M1 - 113352

ER -

Exploring subtalar joint axis alignment in pathological feet of children with cerebral palsy using weight bearing CT

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this